### Describe the usage question you have. Please include as many useful details as possible. When I convert nullable avro schema to nullable arrow schema and write as parquet file, meet a exception "Unhandled type for Arrow to Parquet schema conversion: sparse_union<bigint: int64 not null=5, null: null=0>" It seems arrow-avro not support SPARE_UNION how can I use nullable schema in arrow, please help me. ### Component(s) Java